14 OBSERVATIONS AND MEASUREMENTS ACADEMY MEMBERS 



[Memoirs National 

 [Vol. XXm. 



The above results are practically identical in the three series and show a general advanced 

 reduction in alveolar protrusion. This is due to a generally subdued development, in these con- 

 tingents of the population, of the teeth and of the dental arches. 



Lips 



The lips, as all the other soft parts of the face, change with age. No infant is born with 

 thin lips, but these begin to suggest themselves during childhood, increase in definition and fre- 

 quency during the adult stage, and become common in the old. A potent influence in bringing 

 about the change is the loss of front teeth and absorption of the alveolar processes. Such a loss, it 

 is true, is nowadays generally neutralized by artificial dentures which, if not expertly made, may 

 even accentuate slightly the original alveolar protrusion. In the majority of cases in the aged, 

 however, the alveolar processes have been more or less absorbed and the "plates" tend slightly 

 to underdo rather than overdo the original fullness of the frontal portions of the jaws. This 

 reduces the original protrusion which permits the lips to be drawn more inward and thus to lose 

 in their original external volume. But this agency is secondary to that of the direct effects of 

 age itself on lip diminution. These effects consist evidently of an absorption of some of the 

 tissue of the lips plus, probably, a lessened supply of blood. 



The records on the lips of the members of the Academy show thus: 



Table 17. — Thickness of the lips 



There are, it is seen, rather marked differences in the three series. The available outsiders 

 present a group influenced but very slightly as yet by age, while the members of the Academy 

 and particularly the not old Americans, are affected markedly by their years. Lips above 

 medium in thickness were seemingly once somewhat more common in the members of European 

 birth or parentage than they were in the old Americans both within and outside the Academy ; 

 this is doubtless connected with their racial derivation, a very potent factor in this connection. 



The Chin 



The strength, form, and protrusion of the chin are important physiognomic features. It 

 seems superfluous to insist here on the fact that the differences in the development of the chin 

 and the lower jaw reflect merely the muscular and bony development of the individual and 

 only thus indirectly can have any relation to the "character" of the individual, but this is often 

 forgotten. The two groups of the members of the Academy contrast thus with each other and 

 with the outside old Americans: 



